First of all, let me state the obvious: this is not an independent anime, this is a crossover project with 4 different sources. So, to fully enjoy this title, you should watch at least some (preferably all) of the sources. And when it's done - you will appreciate this title fully, cause all the characters included behave exactly the way they did in original. Or, if you don't - you will miss 90% of humor, cause it is based on originals. Art style may put some people off, but it is the same exact style that was used in short comedy spinoffs, so no problems
here either. There is nothing much to add here, to be honest, cause episodes are short, plot is used only to make some jokes possible, but so far I am enjoying this show a lot, if you are into any of source projects - check this one out.

This is a crossover combination of 4 anime (Overlord, Konosuba, Re:Zero & Youjo Senki), and if you've seen and/or love those anime, you will love this crossover! If you haven't seen those anime, please proceed to watch all of them and then watch this crossover in all its glory! No, but seriously if you haven't seen and/or didn't like those 4 anime, you'll have a very hard time appreciating this show.

Story: 8
True to all the anime its draws from, Isekai Quartet rises above simple fan service with its own unique mystery and story.

Characters: 10
The characters of Overlord, Konosuba, Re:Zero & Youjo Senki are
arguably some of the best parts of those shows, all being richly developed with their own personality and quirks. Isekai Quartet does a fantastic job of using all that character development and building on it. A lot of the humor in Isekai Quartet relies on references and character development from the original animes and honestly I find it really fascinating to see how characters from the different anime interact.

Art: 7
I don't really care for the chibi designs, but I can understand its use as trying to blend the 4 different artistic styles from the 4 source anime would be down right impossible. That being said, you shouldn't be watching this for the art.

Sound: 10
Isekai Quartet sports all the original voice actors and actresses from the original animes, and a good number of them even sing in the opening and ending which is really awesome. Sound quality is nothing short of what we expect from the source animes.

Enjoyment: 10
Like I said before, seeing all my favorite characters from dealing with this unexpected situation and interacting with each other is really interesting and hilarious. I enjoy watching Isekai Quartet immensely.

Overall: 9
I never expected a crossover like this would ever be made, but I'm so glad it was! It totally satisfies my craving to see more of my favorite characters until more sequels for Overlord, Konosuba, Re:Zero & Youjo Senki are released.

🔥 4 Isekai worlds being Isekai'd into another Isekai... and they said that Infinity War was the most ambitious crossover event in history

The anime itself currently presents itself as being quite capable with a good potential to become a funny series, all the most liked characters of each show featured in this show are given a good amount of screen-time right from the first episode and in the coming episodes. In other words, they did a great job at making each viewer of the show content with what they got. It doesn't matter if all you like is Overlord because you'll still love this show
with it's many situations that the overlord characters find themselves in. I think this currently is one of the strong suits of this show.

What's also important to mention is as things are panning out at the moment, each character is as their true self, they haven't needed to change the characters motives, speech nor other way that distinguishes them making it really feel like they've created an anime that has some of the most known "Isekai" characters into one show without a compromise, except for of course the animation and design.

It's very apparent they have changed the way they animated the show just by seeing a couple pictures but what's important to understand is why they did this. Looking at this show from a animators perspective it's quite obvious fully animating characters which are differently animated in each show, with different colors and shading, and even more importantly created by way different Anime studios, it would basically be impossible to really put all the characters into one anime without destroying the whole aesthetic of the anime to begin with, and to be quite honest, with the great dialogue in this show and action I'm pretty sure this really isn't needed!

☄️Story: 8/10:
Though I of course haven't seen everything this show has to offer I think I have seen enough to be able to rate it somewhat with what we currently have.
This show feels structured to say the least.. though things happen very quickly in the show things aren't too hard to understand. One difficulty that first seemed could become a problem, is that when you're basically mushing together 4 different animes into one, many people won't understand the references from the shows... Even this, they have been able to make it easy to follow for someone who is only a real fan one of these shows. This is a great +, and therefore will currently give this show a 8/10

☄️Art: 7/10
Though it's quite apparent that most of the shows focus was not on the actual art of the show, I think it compliments the show very well. It works well together to create a show where the characters kind of feel like they belong, even with their original different art style and so on.
In fact I still really like the art style, it puts characters like the mains from Overlord and Youjo Senki (both quite a bit darker types of shows) into a very different type of "colorful aesthetic look".

☄️Sound: 7/10
I don't think there's much to say here, nothing special, voice acting like in all of these shows is great.

☄️Character: 9/10
This is basically the main part of the shows, the characters. This isn't a new standalone anime in itself, it's an anime that drags multiple animes to create one which has the same charm as the other ones. As I mentioned before, the characters really stand out as being almost the exact same characters like in the original shows.
They act the same way, they talk the same way, they do the same things in similar situations and so on and so on.
Basically a show which was easy to enjoy even with it's simple artstyle.

☄️Enjoyment: 8/10
A show I myself am able to enjoy greatly, the show seems to show no signs of becoming worse after each episode, more so, the complete other way around and only really growing with it's potential.

☄️Overall: 7.8/10
I believe this show will be able to become better over time but will have to give it a 7.8/10 (or basically the score after adding all numbers from before and dividing it by 5)

Thank you for reading my review, I hope to be able to do more reviews in the near future!

An average Joe: “Avengers: Infinity War is the most ambitious crossover ever!”

Me, a cultured anime connoisseur: “Isekai Quartet says hold my out of this world sake!”

Isekai is one of the most hated anime genres of them all. Yet even so, there are a select few Isekai that are generally well received by the anime community for adding unique twists to the genre or by just being entertaining to watch. Four such Isekai anime have been brought together and chibified in order to create the awesomeness that is Isekai Quartet. And so far, it has been a pleasantly enjoyable watch.

Obviously, this is just a lighthearted comedy/parody
series, and is not meant to be taken seriously. It’s simply a fun show to watch if you have some free time. The only preparation that I would recommend before going into this would be viewing the four source anime, since some of the jokes and scenarios will go over your head if you don’t understand the context. This is a mostly character driven series, and so far all of the characters featured have been up to their old antics again with the addition of humorous interactions with the casts of the other Isekai anime. Seeing the main Konosuba cast acting like idiots again, best girl Rem being adorable, Tanya and Ainz going head to head, all of it is just, well, fun!

Whether or not you liked the characters from the four Isekai will most likely make or break how much you enjoy this show. For me, I like practically all of these characters, and seeing them all together in a lighthearted school setting has been quite satisfying.